Friday 4 October 2013 09.00 EDT
First published on Friday 4 October 2013 09.00 EDT

Herodotus is the most entertaining of historians. Indeed, he is as entertaining as anyone who has ever written, historian or not. His great work is many things – the first example of non-fiction, the text that underlies the entire discipline of history, the most important source of information we have for a vital episode in human affairs – but it is above all a treasure trove. This, coming from a translator of The Histories, may sound like special pleading – but it is not. To spend as much time with Herodotus as I have done over these past years has been a rare privilege, a labour of love. The Father of History he may be, but he is also much more than that.

The ostensible goal of The Histories is to explain what would now be termed "the clash of civilisations": the inability of the peoples of east and west to live together in peace. Herodotus was writing within living memory of an event so epic that it continues to thrill and astonish to this day: the repulse in 480BC of a full-scale invasion of Greece, led by the King of Persia, Xerxes. Since the Persian empire was at the time the greatest power on the planet, its defeat struck the Greeks as a barely believable triumph: it was the most astounding victory of all time. Herodotus agreed with this judgment, and his account of the battles of Marathon, Thermopylae and Salamis makes for a narrative as thrilling as one could hope to read. Nevertheless, what is most striking about his history is not any tone of triumphalism, but how lacking it is in chauvinism. Not for nothing was he condemned in antiquity as a philobarbaros – a "lover of barbarians".

The same imperialists who had conquered Herodotus's own native city of Halicarnassus, and brought bloodshed and fire to mainland Greece, are shown in his narrative to possess qualities of nobility and courage. Herodotus notes the premium they set on telling the truth; he admires their hardiness and freely acknowledges that, man for man, they are in no way inferior as warriors to the Greeks. Even his portrait of Xerxes, who has come to serve us (in large part thanks to Herodotus himself) as the archetype of the overweening despot, is touched by moments of glory and pathos. Amid all the millions he led against Greece, Herodotus tells us, there was no one more handsome nor "better fitted to wield supreme power than Xerxes himself". As he watches his army crossing from Asia into Europe, the king feels himself truly blessed – and then begins to weep. When his uncle asks him the reason for his tears, Xerxes answers that he has been "musing on how short is human life, and the pity of it pierced me through. All these multitudes here, and yet, in a hundred years' time, not one of them will be alive."

That the sentiment expressed by Xerxes owes more to the spirit of tragedy than to anything recognisably Persian in no way diminishes the significance of Herodotus's attempts to see events through eyes other than his own. The truth is that he was both intensely a man of his background, and inexhaustibly curious about the world that lay beyond it. What we get in The Histories – as its literal meaning, "inquiries", suggests – is a heroic attempt to push back the frontiers of knowledge on almost every conceivable front. This project, of subjecting the world to historie – "inquiry" – was one bred of the age. Herodotus lived in an intellectual environment that was heady with a sense of discovery, of an infinitude of wonders waiting to be identified and explained without recourse to the supernatural. Only the Enlightenment, perhaps, can compare. Herodotus wrote The Histories in the conviction that they far surpassed anything similar.

And he was right. In part, this was due to the fact that Herodotus was the first to apply to the study of the past the revolutionary new methods of inquiry that were simultaneously transforming how Greek intellectuals understood the natural world: the beginnings of what we now call "science". The premium that Herodotus set on providing sources for his material is now so often taken for granted by historians that it is easy to overlook just how revolutionary it once was. In his account of the buildup to the battle of Plataea, he describes what he has been told by a man called Thersander of Orchomenus, who in turn is reporting what he was told at a banquet by a Persian fellow guest. Men dead for 2,500 years are being given voice. We are witness to the birth pangs of historical method. History is twice‑over being made.

Not everything that Herodotus reports, though, can be so readily sourced. If his concern with the means of gathering evidence is something revolutionary, then so too are the scope and range of his interests. No one before him had ever thought to write on such a heroically panoramic scale. Herodotus understood, to a degree that seems exceptional for his time, that he was living in a globalised era. So vast was the empire of the Persians that its king could dream of leaving no lands beyond its frontiers "for the sun to shine upon". It was the world itself, in Herodotus's opinion, that had been at stake in the great war between the Greeks and the Persians. This was the reason why his inquiry, his historie, was of such universal scope. His ambition was an astonishing one: to encompass the limits of what could humanly be known. Inevitably, this meant that there were occasions when his ability to determine the veracity of information he had come by began to warp and buckle. No one was more aware of this than Herodotus himself. Often, when reporting some wondrous detail, he will surround it with qualifications – expressions of uncertainty or open doubt. Reporting the claim of a Phoenician expedition to have circumnavigated Africa (or "Libya", as he calls it), Herodotus does not conceal his own scepticism. "One of their claims – which I personally find incredible, although others may not – was that, while sailing round Libya, they had had the sun on their right‑hand side."

This is precisely the detail that enables us to know that the Phoenicians were indeed telling the truth and had crossed the equator. That we have no reports of another naval expedition reaching the Cape of Good Hope, until the arrival there in 1488 of the Portuguese, serves to remind us of how Herodotus would operate at the extremes of knowledge. Unsurprisingly, not all the information he obtained was reliable. What are we to make, for instance, of his report of giant Indian ants, "midway between dogs and foxes in size", who dig up gold; or the griffins "who stand guard over gold" in the mountains beyond Scythia? These are the kind of stories that, while they add hugely to the enjoyment of reading The Histories, have resulted in a long tradition of dismissing Herodotus as gullible at best, and at worst a liar. But it's not surprising that he got his facts about India or the wilds beyond Scythia wrong; what's astonishing is that he had any reports about them at all. Only in the new era of Persian imperialism, which for the first time had brought Herodotus's city of Halicarnassus and lands fabulously far to the east under the same rule, would he ever have thought to write about these places. As it happens, a plausible case has been made for both stories being the result of Chinese whispers – in one case, perhaps, literally so. The giant ants, it has been argued, were in fact a breed of Himalayan marmots, which have been known to expose gold-bearing soil when they dig their holes; the griffins, perhaps, were the weathered skeletons of Protoceratops, a dinosaur whose fossils are to be found scattered everywhere in the Gobi desert. Or perhaps not. It is as well to admit, as Herodotus himself did on occasion, that we cannot be sure. Sometimes we simply have to acknowledge the limits of our knowledge. The Histories serve us as the well-spring of historical wisdom as well as of historical method.

Today, when the immensity of the world's learning is available to anyone with an internet connection, it can be harder than ever to think ourselves back into Herodotus's shoes, and a time when the concept of non-fiction writing was still being developed. Yet that is precisely why, now more than ever, it can be so moving to read him. The process of researching and recording facts on a would-be encyclopaedic scale begins with his history. If you have ever used the internet to check up on a fact, then you stand in a line of descent from him. "But if I may digress here," Herodotus says at one point, "as I have sought opportunities to do from the moment I started this account of my inquiries …" This mode of presenting information, which 30 years ago appeared closer in style to Tristram Shandy than to any conventional work of history, will strike most readers as being very familiar. The internet, with its seemingly infinite web of hyperlinks, has provided a whole new metaphor for Herodotus's discursive style of relaying information. When he refers to the capture of Nineveh by the Medes as "an episode I will recount in a later chapter", and then never does so, the frustration for the reader is akin to that of clicking on a broken link. Similarly, the experience of never quite knowing where Herodotus's narrative may lead – to a laugh-out-loud story of a drunk man dancing on a table, perhaps, or to the chilling account of a eunuch's revenge on the man who had him castrated as a child – will be familiar to all who have surfed the web. One definition of a classic, wrote Frank Kermode, is that it "subsists in change, by being patient of interpretation" – and, we might add, patient of translation, too. That alone, I hope, is sufficient justification for my version of The Histories. Herodotus, that most ancient of historians, has always had the capacity to renew himself, and to seem fresh to succeeding generations.

I like to think this would not have surprised him. He knew the scale of what he had embarked on, and the value of what he had achieved. His ambition, as he declared in the opening sentence of the first work of history ever written, was to ensure that "human achievement may be spared the ravages of time". Literally, he spoke of not allowing them to become exitela, a word that could be used in a technical sense to signify the fading of paint from inscriptions or works of art. Today, the colours applied by Herodotus to his portrait of the long-gone world in which he lived remain as exuberant as ever. The ravages of time have indeed been defied.

• Herodotus: The Histories, a new translation by Tom Holland with an introduction by Paul Cartledge, was published last week by Penguin Classics.